From 1975 to 1983, Teachout lived in Kansas City where he worked as a jazz bassist and wrote about classical music and jazz for the Kansas City Star. In 1985, Teachout moved to New York City, where he worked as an editor at Harper's Magazine from 1985 to 1987 and an editorial writer for the New York Daily News from 1987 to 1993. From 1993 to 2000 Teachout was the classical music and dance critic at New York Daily News.

Teachout is the drama critic of The Wall Street Journal and writes a bi-weekly column called "Sightings" about the arts in America for that paper. He is the critic-at-large of Commentary.

Teachout's books include All in the Dances: A Brief Life of George Balanchine (2004),[6]A Terry Teachout Reader (2004), The Skeptic: A Life of H.L. Mencken (2002), and City Limits: Memories of a Small-Town Boy (1991).[7]

Teachout is the editor of Beyond the Boom: New Voices on American Life, Culture, and Politics (1990), which featured an introduction by Tom Wolfe, and Ghosts on the Roof: Selected Journalism of Whittaker Chambers, 1931–1959 (1989).

In 1992, Teachout rediscovered the manuscript of A Second Mencken Chrestomathy among H.L. Mencken's private papers and edited it for publication by Alfred A. Knopf in 1995.[8]

In 2009, Teachout wrote Pops: A Life of Louis Armstrong. "With Pops, his eloquent and important new biography of Armstrong, the critic and cultural historian Terry Teachout restores this jazzman to his deserved place in the pantheon of American artists," Michiko Kakutani wrote in her New York Times review of Pops.[2] The Washington Post chose Pops as one of the ten best books of 2009,[9]The Economist chose it as one of the best books of the year,[10] and the New York Times Book Review chose it as one of the "100 notable books" of 2010.[11]

In 2013, Teachout wrote Duke: A Life of Duke Ellington.[12]Duke was longlisted for the National Book Awards nonfiction prize. James Gavin, writing in the New York Times Book Review, called Duke a "cleareyed reassessment of a man regarded in godlike terms" that "humanizes a man whom history has kept on a pedestal", praising its "sound scholarship and easy readability."[13]Kirkus Reviews called it “an instant classic…Teachout solidifies his place as one of America’s great music biographers.”[14]Publishers Weekly called it “revealing…Teachout neatly balances colorful anecdote with shrewd character assessments and musicological analysis.”[15]

Satchmo at the Waldorf, a one-man-two-character play about Louis Armstrong and Joe Glaser, Armstrong's manager, was premiered at Orlando Shakespeare Theater's Mandell Theatre in Orlando, Fla., on September 15, 2011, in a production starring Dennis Neal and directed by Rus Blackwell. An extensively revised version of Satchmo at the Waldorf in which Miles Davis is also briefly portrayed was produced by Shakespeare & Company of Lenox, Mass., in August 2012, with John Douglas Thompson playing Armstrong, Glaser, and Davis. The production, which transferred to Long Wharf Theatre of New Haven, Conn., in October 2012, and to Philadelphia’s Wilma Theater in November 2012, was directed by Gordon Edelstein.[3] The Boston Globe described the revised version of the play as a "tour de force…Aided by director Gordon Edelstein and the consummately skilled Thompson as interpreter, Teachout—in his debut as dramatist rather than drama critic—has contributed a work of insight and power."[16] According to the New York Times, "Reviewing a play is one thing; writing a play is quite another. Terry Teachout, drama critic for The Wall Street Journal, makes this hat-switching look far easier than it is with his first play…Mr. Teachout has done a fine job of building a fiction-plus-fact theater piece."[17]

Satchmo at the Waldorf transferred to New York's Westside Theatre, an off-Broadway house, on March 4, 2014.[18] It closed there on June 29, 2014, after 18 previews and 136 performances. According to The New Yorker, "Teachout, Thompson, and the director, Gordon Edelstein, together create an extraordinarily rich and complex characterization. The show centers on the trumpeter’s relationship with his Mob-connected Jewish manager of more than thirty-five years, Joe Glaser. Thompson forcefully inhabits both men—and throws in a chilling Miles Davis—delivering an altogether riveting performance."[19] Thompson won the 2013–14 Outer Critics Circle Award and Drama Desk Award for "Outstanding Solo Performance" for his performance in the play.[20][21] It was produced at the Wallis Annenberg Center for the Performing Arts in Beverly Hills, Ca., in May 2015, and at Chicago's Court Theatre, Colorado Springs' Theatreworks, Palm Beach Dramaworks, the Seacoast Repertory Theatre of Portsmouth, N.H., and San Francisco's American Conservatory Theatre during the 2015–16 season. It was produced by New Venture Theatre of Baton Rouge, La., Triangle Productions of Portland, Ore., B Street Theatre of Sacramento, Calif., and the Mosaic Theater Company of Washington, D.C., during the 2016-17 season. The Palm Beach Dramaworks production was directed by Teachout in his professional debut as a stage director.[22] On February 24, 2018, Satchmo opened at the Alley Theatre of Houston in a production directed by Teachout that ran through March 18, 2018; it was performed by Jerome Preston Bates.[23]

Teachout wrote the forewords to Paul Taylor's Private Domain: An Autobiography (1999, University of Pittsburgh Press), Elaine Dundy's The Dud Avocado (2007, New York Review Books Classics), William Bailey's William Bailey on Canvas (2007, Betty Cuningham Gallery), and Richard Stark's Flashfire and Firebreak (2011, University of Chicago Press) and contributed to The Oxford Companion to Jazz (2000, Oxford University Press), Field-Tested Books (2008, Coudal Partners), and Robert Gottlieb's Reading Dance (2008, Pantheon). He also appears in Alex Gibney's Sinatra: All or Nothing at All (2015) and two film documentaries about dance, Mirra Bank's Last Dance (2002) and Deborah Novak's Steven Caras: See Them Dance (2011).